SOS

Small Operating System runs on Raspberry Pi 3 Model B+.

NYCU OSDI Spring 2022 Project.

How to build

• Download dependencies:

sudo apt-get install gcc-aarch64-linux-gnu qemu-system-arm

• Build kernel8.img:

make

• Build kernel8.img with some debug information:

# Options:
#   MM_DEBUG
#   DEMANDING_PAGE_DEBUG
make MM_DEBUG=1
make DEMANDING_PAGE_DEBUG=1

• Build myos.img (which you can dd to SD card):

make image

How to run

• Qemu emulation:

make qemu

• You should either attach gdb to qemu, or just remove the arugments -s -S passed to qemu in the Makefile

• Qemu will emulate the bootloader and you can then attach to the bootloader shell with:

sudo screen /dev/pts/<pts_idx>

• In the bootloader shell, you can use the command load to ask the bootloader to load the kernel image. After entering the load command, you can send the kernel image to the bootloader with the following command:

sudo ./tools/loadkernel.py /dev/pts/<pts_id> build/kernel8.img

How to burn it into pi3

sudo dd if=./build/myos.img of=/dev/<your SD card device>

Directory

Dir	Comment
build	The compiled object files, images of bootloader, kernel, the initramfs.cpio and the fat32 image
img	The files that will be stored to the fat32 image
include	Header files
initramfs	The files that will be stored to the initramfs.cpio (initramfs.cpio will be stored to the fat32 image)
mnt	The tool scripts will use it to create the fat32 image
src	Source code files
tools	Some helper scripts